xref: /linux/arch/mips/kernel/ptrace.c (revision 9d796e66230205cd3366f5660387bd9ecca9d336)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1992 Ross Biro
7  * Copyright (C) Linus Torvalds
8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
9  * Copyright (C) 1996 David S. Miller
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 1999 MIPS Technologies, Inc.
12  * Copyright (C) 2000 Ulf Carlsson
13  *
14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
15  * binaries.
16  */
17 #include <linux/compiler.h>
18 #include <linux/context_tracking.h>
19 #include <linux/elf.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/mm.h>
23 #include <linux/errno.h>
24 #include <linux/ptrace.h>
25 #include <linux/regset.h>
26 #include <linux/smp.h>
27 #include <linux/security.h>
28 #include <linux/tracehook.h>
29 #include <linux/audit.h>
30 #include <linux/seccomp.h>
31 #include <linux/ftrace.h>
32 
33 #include <asm/byteorder.h>
34 #include <asm/cpu.h>
35 #include <asm/dsp.h>
36 #include <asm/fpu.h>
37 #include <asm/mipsregs.h>
38 #include <asm/mipsmtregs.h>
39 #include <asm/pgtable.h>
40 #include <asm/page.h>
41 #include <asm/syscall.h>
42 #include <asm/uaccess.h>
43 #include <asm/bootinfo.h>
44 #include <asm/reg.h>
45 
46 #define CREATE_TRACE_POINTS
47 #include <trace/events/syscalls.h>
48 
49 static void init_fp_ctx(struct task_struct *target)
50 {
51 	/* If FP has been used then the target already has context */
52 	if (tsk_used_math(target))
53 		return;
54 
55 	/* Begin with data registers set to all 1s... */
56 	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
57 
58 	/* ...and FCSR zeroed */
59 	target->thread.fpu.fcr31 = 0;
60 
61 	/*
62 	 * Record that the target has "used" math, such that the context
63 	 * just initialised, and any modifications made by the caller,
64 	 * aren't discarded.
65 	 */
66 	set_stopped_child_used_math(target);
67 }
68 
69 /*
70  * Called by kernel/ptrace.c when detaching..
71  *
72  * Make sure single step bits etc are not set.
73  */
74 void ptrace_disable(struct task_struct *child)
75 {
76 	/* Don't load the watchpoint registers for the ex-child. */
77 	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
78 }
79 
80 /*
81  * Read a general register set.	 We always use the 64-bit format, even
82  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
83  * Registers are sign extended to fill the available space.
84  */
85 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
86 {
87 	struct pt_regs *regs;
88 	int i;
89 
90 	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
91 		return -EIO;
92 
93 	regs = task_pt_regs(child);
94 
95 	for (i = 0; i < 32; i++)
96 		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
97 	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
98 	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
99 	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
100 	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
101 	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
102 	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
103 
104 	return 0;
105 }
106 
107 /*
108  * Write a general register set.  As for PTRACE_GETREGS, we always use
109  * the 64-bit format.  On a 32-bit kernel only the lower order half
110  * (according to endianness) will be used.
111  */
112 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
113 {
114 	struct pt_regs *regs;
115 	int i;
116 
117 	if (!access_ok(VERIFY_READ, data, 38 * 8))
118 		return -EIO;
119 
120 	regs = task_pt_regs(child);
121 
122 	for (i = 0; i < 32; i++)
123 		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
124 	__get_user(regs->lo, (__s64 __user *)&data->lo);
125 	__get_user(regs->hi, (__s64 __user *)&data->hi);
126 	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
127 
128 	/* badvaddr, status, and cause may not be written.  */
129 
130 	return 0;
131 }
132 
133 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
134 {
135 	int i;
136 
137 	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
138 		return -EIO;
139 
140 	if (tsk_used_math(child)) {
141 		union fpureg *fregs = get_fpu_regs(child);
142 		for (i = 0; i < 32; i++)
143 			__put_user(get_fpr64(&fregs[i], 0),
144 				   i + (__u64 __user *)data);
145 	} else {
146 		for (i = 0; i < 32; i++)
147 			__put_user((__u64) -1, i + (__u64 __user *) data);
148 	}
149 
150 	__put_user(child->thread.fpu.fcr31, data + 64);
151 	__put_user(boot_cpu_data.fpu_id, data + 65);
152 
153 	return 0;
154 }
155 
156 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
157 {
158 	union fpureg *fregs;
159 	u64 fpr_val;
160 	int i;
161 
162 	if (!access_ok(VERIFY_READ, data, 33 * 8))
163 		return -EIO;
164 
165 	init_fp_ctx(child);
166 	fregs = get_fpu_regs(child);
167 
168 	for (i = 0; i < 32; i++) {
169 		__get_user(fpr_val, i + (__u64 __user *)data);
170 		set_fpr64(&fregs[i], 0, fpr_val);
171 	}
172 
173 	__get_user(child->thread.fpu.fcr31, data + 64);
174 	child->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
175 
176 	/* FIR may not be written.  */
177 
178 	return 0;
179 }
180 
181 int ptrace_get_watch_regs(struct task_struct *child,
182 			  struct pt_watch_regs __user *addr)
183 {
184 	enum pt_watch_style style;
185 	int i;
186 
187 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
188 		return -EIO;
189 	if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
190 		return -EIO;
191 
192 #ifdef CONFIG_32BIT
193 	style = pt_watch_style_mips32;
194 #define WATCH_STYLE mips32
195 #else
196 	style = pt_watch_style_mips64;
197 #define WATCH_STYLE mips64
198 #endif
199 
200 	__put_user(style, &addr->style);
201 	__put_user(boot_cpu_data.watch_reg_use_cnt,
202 		   &addr->WATCH_STYLE.num_valid);
203 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
204 		__put_user(child->thread.watch.mips3264.watchlo[i],
205 			   &addr->WATCH_STYLE.watchlo[i]);
206 		__put_user(child->thread.watch.mips3264.watchhi[i] & 0xfff,
207 			   &addr->WATCH_STYLE.watchhi[i]);
208 		__put_user(boot_cpu_data.watch_reg_masks[i],
209 			   &addr->WATCH_STYLE.watch_masks[i]);
210 	}
211 	for (; i < 8; i++) {
212 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
213 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
214 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
215 	}
216 
217 	return 0;
218 }
219 
220 int ptrace_set_watch_regs(struct task_struct *child,
221 			  struct pt_watch_regs __user *addr)
222 {
223 	int i;
224 	int watch_active = 0;
225 	unsigned long lt[NUM_WATCH_REGS];
226 	u16 ht[NUM_WATCH_REGS];
227 
228 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
229 		return -EIO;
230 	if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
231 		return -EIO;
232 	/* Check the values. */
233 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
234 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
235 #ifdef CONFIG_32BIT
236 		if (lt[i] & __UA_LIMIT)
237 			return -EINVAL;
238 #else
239 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
240 			if (lt[i] & 0xffffffff80000000UL)
241 				return -EINVAL;
242 		} else {
243 			if (lt[i] & __UA_LIMIT)
244 				return -EINVAL;
245 		}
246 #endif
247 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
248 		if (ht[i] & ~0xff8)
249 			return -EINVAL;
250 	}
251 	/* Install them. */
252 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
253 		if (lt[i] & 7)
254 			watch_active = 1;
255 		child->thread.watch.mips3264.watchlo[i] = lt[i];
256 		/* Set the G bit. */
257 		child->thread.watch.mips3264.watchhi[i] = ht[i];
258 	}
259 
260 	if (watch_active)
261 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
262 	else
263 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
264 
265 	return 0;
266 }
267 
268 /* regset get/set implementations */
269 
270 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
271 
272 static int gpr32_get(struct task_struct *target,
273 		     const struct user_regset *regset,
274 		     unsigned int pos, unsigned int count,
275 		     void *kbuf, void __user *ubuf)
276 {
277 	struct pt_regs *regs = task_pt_regs(target);
278 	u32 uregs[ELF_NGREG] = {};
279 	unsigned i;
280 
281 	for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
282 		/* k0/k1 are copied as zero. */
283 		if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
284 			continue;
285 
286 		uregs[i] = regs->regs[i - MIPS32_EF_R0];
287 	}
288 
289 	uregs[MIPS32_EF_LO] = regs->lo;
290 	uregs[MIPS32_EF_HI] = regs->hi;
291 	uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
292 	uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
293 	uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
294 	uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
295 
296 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
297 				   sizeof(uregs));
298 }
299 
300 static int gpr32_set(struct task_struct *target,
301 		     const struct user_regset *regset,
302 		     unsigned int pos, unsigned int count,
303 		     const void *kbuf, const void __user *ubuf)
304 {
305 	struct pt_regs *regs = task_pt_regs(target);
306 	u32 uregs[ELF_NGREG];
307 	unsigned start, num_regs, i;
308 	int err;
309 
310 	start = pos / sizeof(u32);
311 	num_regs = count / sizeof(u32);
312 
313 	if (start + num_regs > ELF_NGREG)
314 		return -EIO;
315 
316 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
317 				 sizeof(uregs));
318 	if (err)
319 		return err;
320 
321 	for (i = start; i < num_regs; i++) {
322 		/*
323 		 * Cast all values to signed here so that if this is a 64-bit
324 		 * kernel, the supplied 32-bit values will be sign extended.
325 		 */
326 		switch (i) {
327 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
328 			/* k0/k1 are ignored. */
329 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
330 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
331 			break;
332 		case MIPS32_EF_LO:
333 			regs->lo = (s32)uregs[i];
334 			break;
335 		case MIPS32_EF_HI:
336 			regs->hi = (s32)uregs[i];
337 			break;
338 		case MIPS32_EF_CP0_EPC:
339 			regs->cp0_epc = (s32)uregs[i];
340 			break;
341 		}
342 	}
343 
344 	return 0;
345 }
346 
347 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
348 
349 #ifdef CONFIG_64BIT
350 
351 static int gpr64_get(struct task_struct *target,
352 		     const struct user_regset *regset,
353 		     unsigned int pos, unsigned int count,
354 		     void *kbuf, void __user *ubuf)
355 {
356 	struct pt_regs *regs = task_pt_regs(target);
357 	u64 uregs[ELF_NGREG] = {};
358 	unsigned i;
359 
360 	for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
361 		/* k0/k1 are copied as zero. */
362 		if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
363 			continue;
364 
365 		uregs[i] = regs->regs[i - MIPS64_EF_R0];
366 	}
367 
368 	uregs[MIPS64_EF_LO] = regs->lo;
369 	uregs[MIPS64_EF_HI] = regs->hi;
370 	uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
371 	uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
372 	uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
373 	uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
374 
375 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
376 				   sizeof(uregs));
377 }
378 
379 static int gpr64_set(struct task_struct *target,
380 		     const struct user_regset *regset,
381 		     unsigned int pos, unsigned int count,
382 		     const void *kbuf, const void __user *ubuf)
383 {
384 	struct pt_regs *regs = task_pt_regs(target);
385 	u64 uregs[ELF_NGREG];
386 	unsigned start, num_regs, i;
387 	int err;
388 
389 	start = pos / sizeof(u64);
390 	num_regs = count / sizeof(u64);
391 
392 	if (start + num_regs > ELF_NGREG)
393 		return -EIO;
394 
395 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
396 				 sizeof(uregs));
397 	if (err)
398 		return err;
399 
400 	for (i = start; i < num_regs; i++) {
401 		switch (i) {
402 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
403 			/* k0/k1 are ignored. */
404 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
405 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
406 			break;
407 		case MIPS64_EF_LO:
408 			regs->lo = uregs[i];
409 			break;
410 		case MIPS64_EF_HI:
411 			regs->hi = uregs[i];
412 			break;
413 		case MIPS64_EF_CP0_EPC:
414 			regs->cp0_epc = uregs[i];
415 			break;
416 		}
417 	}
418 
419 	return 0;
420 }
421 
422 #endif /* CONFIG_64BIT */
423 
424 static int fpr_get(struct task_struct *target,
425 		   const struct user_regset *regset,
426 		   unsigned int pos, unsigned int count,
427 		   void *kbuf, void __user *ubuf)
428 {
429 	unsigned i;
430 	int err;
431 	u64 fpr_val;
432 
433 	/* XXX fcr31  */
434 
435 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
436 		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
437 					   &target->thread.fpu,
438 					   0, sizeof(elf_fpregset_t));
439 
440 	for (i = 0; i < NUM_FPU_REGS; i++) {
441 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
442 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
443 					  &fpr_val, i * sizeof(elf_fpreg_t),
444 					  (i + 1) * sizeof(elf_fpreg_t));
445 		if (err)
446 			return err;
447 	}
448 
449 	return 0;
450 }
451 
452 static int fpr_set(struct task_struct *target,
453 		   const struct user_regset *regset,
454 		   unsigned int pos, unsigned int count,
455 		   const void *kbuf, const void __user *ubuf)
456 {
457 	unsigned i;
458 	int err;
459 	u64 fpr_val;
460 
461 	/* XXX fcr31  */
462 
463 	init_fp_ctx(target);
464 
465 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
466 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
467 					  &target->thread.fpu,
468 					  0, sizeof(elf_fpregset_t));
469 
470 	for (i = 0; i < NUM_FPU_REGS; i++) {
471 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
472 					 &fpr_val, i * sizeof(elf_fpreg_t),
473 					 (i + 1) * sizeof(elf_fpreg_t));
474 		if (err)
475 			return err;
476 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
477 	}
478 
479 	return 0;
480 }
481 
482 enum mips_regset {
483 	REGSET_GPR,
484 	REGSET_FPR,
485 };
486 
487 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
488 
489 static const struct user_regset mips_regsets[] = {
490 	[REGSET_GPR] = {
491 		.core_note_type	= NT_PRSTATUS,
492 		.n		= ELF_NGREG,
493 		.size		= sizeof(unsigned int),
494 		.align		= sizeof(unsigned int),
495 		.get		= gpr32_get,
496 		.set		= gpr32_set,
497 	},
498 	[REGSET_FPR] = {
499 		.core_note_type	= NT_PRFPREG,
500 		.n		= ELF_NFPREG,
501 		.size		= sizeof(elf_fpreg_t),
502 		.align		= sizeof(elf_fpreg_t),
503 		.get		= fpr_get,
504 		.set		= fpr_set,
505 	},
506 };
507 
508 static const struct user_regset_view user_mips_view = {
509 	.name		= "mips",
510 	.e_machine	= ELF_ARCH,
511 	.ei_osabi	= ELF_OSABI,
512 	.regsets	= mips_regsets,
513 	.n		= ARRAY_SIZE(mips_regsets),
514 };
515 
516 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
517 
518 #ifdef CONFIG_64BIT
519 
520 static const struct user_regset mips64_regsets[] = {
521 	[REGSET_GPR] = {
522 		.core_note_type	= NT_PRSTATUS,
523 		.n		= ELF_NGREG,
524 		.size		= sizeof(unsigned long),
525 		.align		= sizeof(unsigned long),
526 		.get		= gpr64_get,
527 		.set		= gpr64_set,
528 	},
529 	[REGSET_FPR] = {
530 		.core_note_type	= NT_PRFPREG,
531 		.n		= ELF_NFPREG,
532 		.size		= sizeof(elf_fpreg_t),
533 		.align		= sizeof(elf_fpreg_t),
534 		.get		= fpr_get,
535 		.set		= fpr_set,
536 	},
537 };
538 
539 static const struct user_regset_view user_mips64_view = {
540 	.name		= "mips64",
541 	.e_machine	= ELF_ARCH,
542 	.ei_osabi	= ELF_OSABI,
543 	.regsets	= mips64_regsets,
544 	.n		= ARRAY_SIZE(mips64_regsets),
545 };
546 
547 #endif /* CONFIG_64BIT */
548 
549 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
550 {
551 #ifdef CONFIG_32BIT
552 	return &user_mips_view;
553 #else
554 #ifdef CONFIG_MIPS32_O32
555 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
556 		return &user_mips_view;
557 #endif
558 	return &user_mips64_view;
559 #endif
560 }
561 
562 long arch_ptrace(struct task_struct *child, long request,
563 		 unsigned long addr, unsigned long data)
564 {
565 	int ret;
566 	void __user *addrp = (void __user *) addr;
567 	void __user *datavp = (void __user *) data;
568 	unsigned long __user *datalp = (void __user *) data;
569 
570 	switch (request) {
571 	/* when I and D space are separate, these will need to be fixed. */
572 	case PTRACE_PEEKTEXT: /* read word at location addr. */
573 	case PTRACE_PEEKDATA:
574 		ret = generic_ptrace_peekdata(child, addr, data);
575 		break;
576 
577 	/* Read the word at location addr in the USER area. */
578 	case PTRACE_PEEKUSR: {
579 		struct pt_regs *regs;
580 		union fpureg *fregs;
581 		unsigned long tmp = 0;
582 
583 		regs = task_pt_regs(child);
584 		ret = 0;  /* Default return value. */
585 
586 		switch (addr) {
587 		case 0 ... 31:
588 			tmp = regs->regs[addr];
589 			break;
590 		case FPR_BASE ... FPR_BASE + 31:
591 			if (!tsk_used_math(child)) {
592 				/* FP not yet used */
593 				tmp = -1;
594 				break;
595 			}
596 			fregs = get_fpu_regs(child);
597 
598 #ifdef CONFIG_32BIT
599 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
600 				/*
601 				 * The odd registers are actually the high
602 				 * order bits of the values stored in the even
603 				 * registers - unless we're using r2k_switch.S.
604 				 */
605 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
606 						addr & 1);
607 				break;
608 			}
609 #endif
610 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
611 			break;
612 		case PC:
613 			tmp = regs->cp0_epc;
614 			break;
615 		case CAUSE:
616 			tmp = regs->cp0_cause;
617 			break;
618 		case BADVADDR:
619 			tmp = regs->cp0_badvaddr;
620 			break;
621 		case MMHI:
622 			tmp = regs->hi;
623 			break;
624 		case MMLO:
625 			tmp = regs->lo;
626 			break;
627 #ifdef CONFIG_CPU_HAS_SMARTMIPS
628 		case ACX:
629 			tmp = regs->acx;
630 			break;
631 #endif
632 		case FPC_CSR:
633 			tmp = child->thread.fpu.fcr31;
634 			break;
635 		case FPC_EIR:
636 			/* implementation / version register */
637 			tmp = boot_cpu_data.fpu_id;
638 			break;
639 		case DSP_BASE ... DSP_BASE + 5: {
640 			dspreg_t *dregs;
641 
642 			if (!cpu_has_dsp) {
643 				tmp = 0;
644 				ret = -EIO;
645 				goto out;
646 			}
647 			dregs = __get_dsp_regs(child);
648 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
649 			break;
650 		}
651 		case DSP_CONTROL:
652 			if (!cpu_has_dsp) {
653 				tmp = 0;
654 				ret = -EIO;
655 				goto out;
656 			}
657 			tmp = child->thread.dsp.dspcontrol;
658 			break;
659 		default:
660 			tmp = 0;
661 			ret = -EIO;
662 			goto out;
663 		}
664 		ret = put_user(tmp, datalp);
665 		break;
666 	}
667 
668 	/* when I and D space are separate, this will have to be fixed. */
669 	case PTRACE_POKETEXT: /* write the word at location addr. */
670 	case PTRACE_POKEDATA:
671 		ret = generic_ptrace_pokedata(child, addr, data);
672 		break;
673 
674 	case PTRACE_POKEUSR: {
675 		struct pt_regs *regs;
676 		ret = 0;
677 		regs = task_pt_regs(child);
678 
679 		switch (addr) {
680 		case 0 ... 31:
681 			regs->regs[addr] = data;
682 			break;
683 		case FPR_BASE ... FPR_BASE + 31: {
684 			union fpureg *fregs = get_fpu_regs(child);
685 
686 			init_fp_ctx(child);
687 #ifdef CONFIG_32BIT
688 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
689 				/*
690 				 * The odd registers are actually the high
691 				 * order bits of the values stored in the even
692 				 * registers - unless we're using r2k_switch.S.
693 				 */
694 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
695 					  addr & 1, data);
696 				break;
697 			}
698 #endif
699 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
700 			break;
701 		}
702 		case PC:
703 			regs->cp0_epc = data;
704 			break;
705 		case MMHI:
706 			regs->hi = data;
707 			break;
708 		case MMLO:
709 			regs->lo = data;
710 			break;
711 #ifdef CONFIG_CPU_HAS_SMARTMIPS
712 		case ACX:
713 			regs->acx = data;
714 			break;
715 #endif
716 		case FPC_CSR:
717 			child->thread.fpu.fcr31 = data & ~FPU_CSR_ALL_X;
718 			break;
719 		case DSP_BASE ... DSP_BASE + 5: {
720 			dspreg_t *dregs;
721 
722 			if (!cpu_has_dsp) {
723 				ret = -EIO;
724 				break;
725 			}
726 
727 			dregs = __get_dsp_regs(child);
728 			dregs[addr - DSP_BASE] = data;
729 			break;
730 		}
731 		case DSP_CONTROL:
732 			if (!cpu_has_dsp) {
733 				ret = -EIO;
734 				break;
735 			}
736 			child->thread.dsp.dspcontrol = data;
737 			break;
738 		default:
739 			/* The rest are not allowed. */
740 			ret = -EIO;
741 			break;
742 		}
743 		break;
744 		}
745 
746 	case PTRACE_GETREGS:
747 		ret = ptrace_getregs(child, datavp);
748 		break;
749 
750 	case PTRACE_SETREGS:
751 		ret = ptrace_setregs(child, datavp);
752 		break;
753 
754 	case PTRACE_GETFPREGS:
755 		ret = ptrace_getfpregs(child, datavp);
756 		break;
757 
758 	case PTRACE_SETFPREGS:
759 		ret = ptrace_setfpregs(child, datavp);
760 		break;
761 
762 	case PTRACE_GET_THREAD_AREA:
763 		ret = put_user(task_thread_info(child)->tp_value, datalp);
764 		break;
765 
766 	case PTRACE_GET_WATCH_REGS:
767 		ret = ptrace_get_watch_regs(child, addrp);
768 		break;
769 
770 	case PTRACE_SET_WATCH_REGS:
771 		ret = ptrace_set_watch_regs(child, addrp);
772 		break;
773 
774 	default:
775 		ret = ptrace_request(child, request, addr, data);
776 		break;
777 	}
778  out:
779 	return ret;
780 }
781 
782 /*
783  * Notification of system call entry/exit
784  * - triggered by current->work.syscall_trace
785  */
786 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
787 {
788 	long ret = 0;
789 	user_exit();
790 
791 	current_thread_info()->syscall = syscall;
792 
793 	if (secure_computing() == -1)
794 		return -1;
795 
796 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
797 	    tracehook_report_syscall_entry(regs))
798 		ret = -1;
799 
800 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
801 		trace_sys_enter(regs, regs->regs[2]);
802 
803 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
804 			    regs->regs[6], regs->regs[7]);
805 	return syscall;
806 }
807 
808 /*
809  * Notification of system call entry/exit
810  * - triggered by current->work.syscall_trace
811  */
812 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
813 {
814         /*
815 	 * We may come here right after calling schedule_user()
816 	 * or do_notify_resume(), in which case we can be in RCU
817 	 * user mode.
818 	 */
819 	user_exit();
820 
821 	audit_syscall_exit(regs);
822 
823 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
824 		trace_sys_exit(regs, regs->regs[2]);
825 
826 	if (test_thread_flag(TIF_SYSCALL_TRACE))
827 		tracehook_report_syscall_exit(regs, 0);
828 
829 	user_enter();
830 }
831